Siphonic air-lift trap



W. R. BRANDAU SIPHONIC AIR LIFT TRAP April 18, 1933.

Filed Jan. 16, 1932 Patented Apr. 18, 1933 i Unire!) STATS WALTER .'R..BRANDAU, OF LOS ANGELES, CALIFORNIA sim-Ionic Aint-LIFT TRAP Applicationfiled January 16, 1982. Serial No. 587,077.

In this specification, and the accompanyying drawing, I shall describeand show a preferred form of my invention, and specifically mentioncertain of its more important bjects. I do not limit myself tothe formsdisclosed, since various changes and adaptations may be made thereinwithout departing fromV the essence of my invention as hereinafterclaimed; and objects and advantages,

'10 otherthan those specifically mentioned, are

included within its scope. v

My invention relates to devices of the class vcommonly designated asair-lifts, for pumping water or other liquids by means of compressedair, without employing mechanism or moving parts. Among its salientobjects are: first, to provide a greatly improved device of this nature,that is adapted for higher lifts, and for use in deeper wells, than thetypes of air-lifts that hitherto have been employed; second, to providean air-lift that is adapted for securing greater operating efficiencythan has previously been possible; third, to'secure, in such a device, auniformly continuous discharge; and, fourth, to accomplish the above bymeans of relatively simple and inexpensive apparatus.

My objects are attained in the manner illustrated in the accompanyingdrawing, in which :--y

Figure'l is a sectional elevation of a well with my improved devicetherein, the apparatus being shown broken for convenience ofillustration; and partly in elevation and partly incentral section;

Figure 2 is a plan view of the Well and of my apparatus therein; and YFigure 3 is a view of the bottom of the apparatus, as it would appearwhen looking 40 upwardly thereat.

kSimilar reference numerals refer to similar parts throughout theseveral views.

In all air-lift pumping apparatus, utilization is made of the principlethat a column of fluid that is partly mixed with air, is of less weightthan a column of homogeneous liquid of similarheight. The first devicesof this nature were relativelyV crude, and consisted essentially o-f acompressed air nozzle directed upwardly in the lower endof the that, ineffect, it resembles a froth.

discharge pipe, the latter being submerged in the well to be pumped. Insuch devices, thel air discharged from the nozzle creates what arecommonly termed air pistons, spaced by short columns of liquid; and thewhole composite mass of liquid and air moves upwardly within thedischarge line by reason of the continuous formation of new airpistons,` and the fact that the composite contents of the discharge lineweigh less than 6o a corresponding column of the homogeneous liquid thatsurrounds the discharge line on the outside. Such a device is effectiveto pump liquids, but obviously the discharge occurs as intermittentalternating quantities of liquid and air. The'power required foroperating such devicesfluctuates rapidly, by reason of the intermittentnature of the discharge; and other operative diculties are caused bythis intermittent action.

Later devices attempty to overcome the above difliculties by comminglingthe liquid and air, in such mannerV that the discharge column willconsist of liquid containing relatively small bubbles of air, uniformlydispersed through the mass. Y

I have discovered a method, and provided apparatus, for securing in thedischarge column, liquid that is uniformly mixed with a vast number ofvery small air bubbles; so S0 This results in an exceedingly uniformdischarge that is free from pulsations, and that requires a uniformin-put of power. v

One of the principal advantages of securing the vabove result willbecome apparent when attention isv called to the Well known fact thatthe eciency graph of practically all prime movers, such as electricmotors, is curvilinear; and this efficiency reaches its maximum at apoint somewhere near the capacity of the power source. If, for instance,an electric motor is operated at any other load than that for which itisdesigned, its eiiiciency will be lower than its maximum efficiency. Inthe 95 `case of a motor employed for causing a pulsating discharge flow,the output of the motor necessarily will be pulsating, and its operatping efficiency cannot be at the maximum throughout its operating cycle.By securing a uniform discharge flow, which my apparatus is adapted forproviding, a suitable prime mover may be employed in such manner as tooperate continuously at its maximum eiliciency.

Passing to a detailed description of my invention, I have illustrated asection of a deep well, lined with a casing 5. My apparatus is depictedin operative relation to this well, except that no attempt has been madeto illustrate the homogeneous-liquid inthe well, or the composite fluidin the discharge line. To do this would be difficult, and it wouldresult in confusing the drawing. It has therefore been thought better torefer to the -following description, as to the action of the device inbreaking up the liquid and commingling it with air. It will beunderstood that the apparatus'is necessarily submerged when it is beingoperated.

At 6 I have shown the lower end ofthe discharge line from the apparatus.This line may be made up of pipe leading to the top of the well, andtherefrom to the point where the discharge is to be delivered. The lowerend of the discharge line is attached to the air-lift apparatus proper,by any suitable means, a by the screwed coupling 7.

My air-lift comprises an outer cylindrical shell 8, closed at the top bymeans of the dome fitting 9, which is screwed into coupling 7. Aco-axial inner barrel 10, of the same diameter as the dischargeline,extends downwardly within the outer'shell to a point relativelynear the bottom. A co-axial booster nozzle 11 extends upwardly intobarrel 10 from the bottom of the device, throughthe spheroidal bottomfof an intermediate cylinder 12. The diameter of this intermediatecylinder is considerably larger than that of the barrel 10,

and is smaller than that of shell 8. It is open ended at the ton, and isspaced and supported in co-axial relation to the inner barrel and outershellby means of riveted studs 13, of which one is shown.

At the bottom of the device is a co-axial intake nozzle 14,V extendingupwardly into the shell for a small distance. This nozzle is surroundedby a compressed air chamber 15 of substantial volume and the outer wall16 of this chamber is so shaped, and cooperates with the wall of theintake nozzle in such a manner, as to form a narrow annular blastorifice at 17 surrounding the upper extremity Vof the intake nozzle.

and three other air pipes, designated 22, lead into the bot-tom ofchamber 15 at points spaced approximately 12() degrees, as indicated inFig. 3.

I prefer to employ ball valves at or near the outlets of each of thelast mentioned air pipes, as indicated at 23 and 24; for the purpose ofavoiding possible silting troubles when the device remains idle in thewell for considerable periods. I have found that it is relatively easyto blow out such silt deposits as can occur above the valves, but thatit is more difficult to dislodge silt when it accumulates in thenecessary U-bends at the lower ends of the air pipes.

Then-the above described device has been loweredinto a well, suspendedfrom the lower extremity of discharge line 6, and submerged a suhcientdepth below the liquid level of the well, compressed air is suppliedthrough line 19 and distributed by means of fitting 18 to the smallerair pipes 21 and 22. Chamber 15 will thus be filled with compressed airthat willbe discharged therefrom upwardly through the annular orifice 17at high velocity, as indicated by arrow 26. Thiswill have the eil'ect ofdrawing the liquid of the well into intake nozzle 14, as indicated byarrow 27. Theair blast will surround the column of incoming liquid, andimpinge upon it by reason'of the converging directions of the respectiveflows. This will result in separating the liquidinto small particles,and cause it to become avmixture ofliquid and air. spheroidal bottom ofcylinder 12, with a tendency to further break up the ybodies of liquidinto smaller particles. The mixture of liquid and air will then passupwardly through annular passage 28, impinge upon the inner surface ofdome 9 at 29, and be reflected from the latter downwardly into annularpassage 30, as indicated by arrow 31. At the bottom of this passage themixture of air and liquid will again be reflected by the upper surfaceof the spheroidal bottom of cylinder 12, as indicated by arrow 32, andthen pass upwardly into bariel lO'and the discharge line.

From this point the mixture of liquid and air would naturally rise inthe discharge line, by reason of its being of less weight than thecorresponding surrounding column of liquid in the well; providing thedischarge head `is not too great, and that the device has beensuiliciently submerged. However, to secure a more rapid discharge, toprovide means for discharge against a. greater head, and to make a.smaller submergence necessary, the booster nozzle 11 is provided.Compressed air discharged from this nozzle, as indicated by arrow33,1101; only acts directly upon the column in the discharge line tomove it upwardly by reason of the direct pressure exerted thereon, butit will have the effect of This mixture willimpinge upon the furtheraerating the column in the discharge line to lessen its weight, and to'further break up the mixture in the discharge line into very smallparticlesl of liquid linterspersed with very small air bubbles.

It vwill be noted thatfair blasts from annular nozzle 17 and booster''nozzle 1 1 impinge directly upon vthe liquid. It willy be noted furtherthat the mixture of liquid and air impinges upon the reflecting surfacesof the bottom of cylinder 12, and dome 9. A Still further, it will beseen that at the points indicated by Varrows 31 and 32, the direction ofthe fluid is reversed; thereby creating great turbulence. As a result ofall t-hese actions, the liquid becomes very finely divided, andinterspersed with very small air bubbles, so that when it is discharged,it is in the nature of a froth that iows very uniformly and withoutpulsations. Obviously, the power required for pumping such a mixturewill be very uniform, and may be provided by a prime source of poweroperating at its maximum efliciency.

For purposes of illustration, the construction of the device has beensimplified as far as possible but, nevertheless, a perfectly practicalform of construction has been shown. The annular pressure chamber infitting 18 may be made in casting the fitting, by coring. The dome 9 maybe made as a casting, by swaging or by welding. The various shells maybe assembled by screwing together as shown, or they may be rivetedtogether. The air chamber 15 may be built up of swaged or pressedmaterial, welded together, and bosses 34 may be welded to the bottomthereof.

By providing a screw thread 35 at the lower end of intake nozzle 14, itis possible to attach atail pipe to the device for reaching the ultimatebottom of a well. ln such case it will be necessary to remove the U-bendat the lower extremity of pipe 21, and to connect up booster nozzle 11with the air supply in some other manner. This can be done by leadingair pipe 21 through the side of shell 8 and through the wall ofintermediate cylinder 12. Ball valve 24, if it is desired to retain it,should then be located within cylinder 12.

I sometimes find it desirable to make a number of small perforations 36in the outer wall of air chamber 15, to further assist in aerating theliquid. The advantage of employing these will depend uponvariousoperating conditions; such as'the submergence, the height of the lift,and the available air pressure for operating the device.

lt will be understood that the length of the device, if properlydesigned, will be much greater than Fig. 1 would indicate. Theinspira-tory action of annular orifice 17 will also be fully understoodby those familiar with this art. Y

I desire to call particular attention to the fact that varioussucceeding steps in the functioning of my device, although primarily forthe purpose of converting the incoming liquid into finely dividedparticles mixed with minute air bubbles, will assist in moving themixture and overcoming its frictional resistance. Thus the down-fallingmixture in annular passage 30 willexert a siphonic effect capable oflifting practically the same height of mixture in annular passage 2S;and the inspiratory action of booster nozzle 11 will strongly aid inmoving the `mixture through the preceding passages'of the device.

Having thus fully described'my invention, l claim: d

1. A device of the character described, comprising; an intake nozzle; asurface above the inner end of said nozzle adapted to deflect a flowimpinging thereagainst .a narrow annular passage surrounding the innerend of said nozzle whereby an annular jet may bev caused, to draw liquidinto the device through said nozzle, and toimpinge upon said liquidafter it has been defiectedby said surface; and means for dischargingthe liquid fromk said device. l

2. A device of the character described, comprising; a ycentral intakenozzle at the bottom; a. surface above the inner end of said nozzleadapted to deflect outwardly and upwardly an upward flow of liquidimpinging thereagainst; a narrow annular passage surrounding the innerend of said nozzle, adapted for forming an annular inspiratory jet forcausing liquid to vbe drawn into the device through said nozzle; andmeans for discharging the liquid from said device; the annular passagebeing so directed as to cause the jet issuing therefrom to impinge uponsaid liquid after it has been'deiiected by said surface. i Y

3. A device of the character described, comprising; a central intakenozzle at the bottom; ay surface above the inner end of said nozzleadapted to deflect outwardly` and upwardly an upward flow of liquidimpinging thereagainst; a pressure chamber surrounding the lower end ofsaid nozzle; a narrow annular passa-ge surrounding the inner end of saidnozzle and communicating directly with said chamber; and means fordischarging the liquid from said device; said passage being adapted forforming an annular inspiratoryjet for causing liquid to be drawn intothe device through said-nozzle, and, being so directed as to cause thejet issuing therefrom*I .to impinge upon 1 said liquid after it hasbeen' deflected by said surface. y i

4. A device of the character described, comprising; a centralk intakenozzle at the bottom.; a spheroidal surface above the inner end of saidnozzle adapted to deflect outwardly. and upwardly `an upwardl flow ofliquid impinging thereagainst; a pressure chamber of substantial volumesurrounding the lower end of said nozzle; means for conductingcompressed air into said chamber; a. narrow annular passage surroundingthe inner extremity of said nozzle and communicating directly with saidchamber; and means for discharging the liquid from said device; saidpassage being adapted for forming an annular inspiratory air jet suitedfor causing liquid to be drawn into the device through said nozzle, andbeing so directed as to cause the jet issuing therefrom to impinge uponsaid liquid after it has been deflected by said surface, and so as tobreak up the body of liquid and pr'oduce a mixture of liquid and airbubbles- 5. The construction set forth in claim 4, in combination withmeans for imparting an additional velocity head to the mixture of liquidand air.

6. The Vconstruction set forth in claim 4, in combination with air-jetmeans or imparting an additional velocity head to the mixture in saiddischarge line.

7. The construction set forth in claim 4, in combination with g' meansfor causing said mixture to impinge u on deflecting surfaces, forreversing its flow irection, and for thereby creating turbulence forbreaking up the mixture into still smaller particles of liquid and air;and air-jet means in the discharge line for adding additional air to themixture while imparting an additional velocity head thereto.`

8. The construction set forth in claim 4, in combination with; means forcausing said mixture to impinge` upon deflecting surfaces, for reversingits flow direction, and for thereby creating turbulence for breaking upthe mixture into still smaller particles of liquid and air; intermediatesiphonic means forV assisting the movement of mixture through thepassages of the device; and air-jet means in the discharge line foradding additional air to the mixture while imparting an additionalvelocity head thereto.

9. A device of the character described, comprising; an outer cylindricalshell that is closed at the top ;V a. co-axial discharge line leadingfrom a point in the interior of the shell near its bottom, and upwardlythrough its top; a co-axial open-top cylinder with a closed bottomwithin the shell, spaced from the inner wall of the shell and the outerwall of the discharge line; air-j et means for drawing liquid into thebottom of the shelland thereafter forcing it consecutively upwardly anddownwardly through the angular passages formed by said cylinder and saidwalls; and upwardly directed air-jet means within the discharge line atthe lower end thereof.

10. A device of the character described, comprising; an outercylindrical shell that is closed at the top; a co-axial discharge lineand upwardly directed air-jet means within the discharge line at thelower end thereof. WALTER R. BRANDAU.

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